ANALYSIS ON THREAD STRIPPING OF WHEEL BOLT DURING ASSEMBLY

The thread of wheel bolt stripped during assembly. The results of the test showed that no defects were detected with dimensions, metallographic structure, hardness and thread surface of the bolt. But there were obvious differences on the quality of chromium plating layer between failed bolt and imported one. It was concluded that the failure of the thread was mainly due to the uneven thickness distribution of the plating layer, and the hardness of plating layer didn′t match to that of the bolt material. The plating layer was non uniformly squeezed, deformed and peeled off when load was added during assembly, and then the bolt was damaged.